1. Field of the Invention
The present invention relates generally to magnetic field applications and antenna arrangements, such as those used in radio frequency identification systems and related identification/recognition fields and, in particular, to an antenna arrangement for providing increased signal recognition and identification properties.
2. Description of the Related Art
In the field of identification and recognition systems and, for example in the field of radio frequency (RFID) identification systems, a system must be provided to allow for the communication between a reader/recognizer and an item, such as a tagged item. The identification is typically accomplished by generating a field, such as a magnetic field, capable of interacting with and communicating with an identification element, such as a tag, positioned on the item. The field can either activate or power the tag, in a passive system, or the tag may include internal power sources to facilitate communications with the system reader/recognizer. The magnetic field is typically generated by applying a current to an antenna, such as an antenna wire and the like. Accordingly, the antenna is powered and emits the field, which is used in identifying object or items within the field.
One drawback in the field and art of tag recognition, such as in the field of inventory systems, is the inability of the reader to identify tags that are positioned in “dead” areas or otherwise oriented in unreadable positions, such as perpendicular to the reader-generated field. Accordingly, there is a need in the art to provide systems with improved identification functionalities, capable of reading a tag, and therefore identifying an item, regardless of item or tag orientation or position within the system or container.
One manner of creating such improved identification characteristics is by the provision of a three-dimensional magnetic pattern. Such prior art systems, however, require complex antenna arrangements in order to produce such a field. For example, see U.S. Pat. No. 6,696,954 to Chung. In particular, these prior art systems require an antenna, positioned on each of the X-, Y- and Z-axis. One drawback to this method and arrangement is that only the tag (transponder) closest to the antennae reader has the maximum energy transfer, and in order to obtain a three-dimensional magnetic field, a cube (X-Y-Z) form is required. For example, in order to identify and read the array of transponders or tags when positioned close together a change in the transponder located by the end of the array is required, which will not otherwise be identified due to low power magnetic field in that position.
According to the prior art,
It is, therefore, an object of the present invention to provide an antenna arrangement that overcomes the deficiencies and drawbacks evidenced in the prior art antenna arrangements in the field of recognition and inventory systems. It is another object of the present invention to provide an antenna arrangement that produces or provides a single-axis three-dimensional magnetic field that does not require a complex antenna arrangement on multiple axes. It is a still further object of the present invention to provide an antenna arrangement that produces or provides a single-axis three-dimensional magnetic field that improves tag/item identification, regardless of positioning and stacking. It is yet another object of the present invention to provide an antenna arrangement that produces or provides a single-axis three-dimensional magnetic field that provides improved energy transfer and identification/communication characteristics.
Accordingly, the present invention is directed to an antenna arrangement having a first antenna module. The first antenna module includes a first antenna loop positioned in a plane for emitting a signal in a first spatial area, and at least one additional antenna loop positioned in substantially the same plane for emitting a signal in an additional spatial area. The arrangement includes at least one power source in communication with the first antenna module for providing current. The first spatial area and the additional spatial area at least partially overlap, and the first antenna loop and the additional antenna loop are configured to be powered by the power source in specified pattern.
The present invention is also directed to an antenna arrangement having a first antenna module and a second antenna module. The first antenna module is positioned in a plane and includes a first antenna loop configured for emitting a signal in a first spatial area, and at least one additional antenna loop for emitting a signal in an additional spatial area. The first spatial area and the additional spatial area at least partially overlap. The second antenna module is substantially aligned with, positioned substantially in the same plane as and oriented at about 90° with respect to the first antenna module. Further, the second antenna module includes a first a first antenna loop for emitting a signal in a first spatial area, and at least one additional antenna loop for emitting a signal in an additional spatial area. In this second antenna module, the first spatial area and the additional spatial area at least partially overlap. The arrangement also includes at least one power source in communication with the first antenna module and the second antenna module for providing power. The first antenna loop and the additional antenna loop of the first and second antenna modules are configured to be powered by the at least one power source in specified pattern.
Further, the present invention is directed to a method of identifying at least one item. This method includes the steps of: (a) providing a first antenna loop positioned in a plane and configured to emit a signal in a first spatial area; (b) providing at least one additional antenna loop positioned in substantially the same plane and configured to emit a signal in an additional spatial area; (c) powering the first antenna loop to thereby emit a signal in a first spatial area; and (d) powering the additional antenna loop to thereby emit a signal in an additional spatial area. The first spatial area and the additional spatial area at least partially overlap, and the first antenna loop and the additional antenna loop are configured to be powered in specified pattern.
These and other features and characteristics of the present invention, as well as the methods of operation and functions of the related elements of structures and the combination of parts and economies of manufacture, will become more apparent upon consideration of the following description and the appended claims with reference to the accompanying drawings, all of which form a part of this specification, wherein like reference numerals designate corresponding parts in the various figures. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only and are not intended as a definition of the limits of the invention. As used in the specification and the claims, the singular form of “a”, “an”, and “the” include plural referents unless the context clearly dictates otherwise.
For purposes of the description hereinafter, the terms “upper”, “lower”, “right”, “left”, “vertical”, “horizontal”, “top”, “bottom”, “lateral”, “longitudinal” and derivatives thereof shall relate to the invention as it is oriented in the drawing figures. However, it is to be understood that the invention may assume various alternative variations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification, are simply exemplary embodiments of the invention. Hence, specific dimensions and other physical characteristics related to the embodiments disclosed herein are not to be considered as limiting.
It is to be understood that the invention may assume various alternative variations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification, are simply exemplary embodiments of the invention.
The present invention is directed to an antenna arrangement 10 and system for use in connection with recognition systems and radio frequency identification (RFID) applications. For example, the antenna arrangement 10 of the present invention is useful in connection with an inventory system that is used to identify, recognize and inventory multiple items 100, with each item 100 or groups of items 100 being in operative communication with a tag 102. The tag 102 typically includes a transponder for emitting a signal, and it is envisioned that the tags 102 can be passive tags 102, which are energized by a field emitting from a reader, such as an antenna, or an active tag, which includes its own discrete power source. The present invention is equally useful with any of these different styles and operations of tags 102, as is known in the art.
The antenna arrangement 10 includes a first antenna module 12, and this first antenna module 12 includes a first antenna loop 14, which is positioned in a plane and configured to emit a signal in a first spatial area 16. In addition, the first antenna module 12 includes at least one additional antenna loop 18, which is positioned substantially in the same plane as the first antenna loop 14. Further, as with the first antenna loop 14, the additional antenna loop 18 is configured to emit a signal in an additional spatial area 20. Still further, the first spatial area 16 and the additional spatial area 20 at least partially overlap. Both the first antenna loop 14 and the additional antenna loop 18 may be positioned on a common and substantially planar substrate 21.
In order to emit a signal or field, the first antenna loop 14 and the additional antenna loop 18 are in operative communication with and powered by a power source 22. In particular, the power source 22 provides current to the antenna loop 14, 18, causing the antenna loop 14, 18 to emanate a signal or field and, thereby, activate the tag 102 attached to the item 100. Accordingly, regardless of whether the tag 102 is an “active” tag or a “passive” tag, the signal emitted from the tag 102 (or the transponder) is captured by the first antenna loop 14 and/or the additional antenna loop 18 and transferred to a reader 24.
Due to the overlapping antenna loops 14, 18 and, consequently, spatial areas 16, 20, the resulting coverage of the field or signal emitted from the antenna loops 14, 18 is maximized. In addition, the antenna loops 14, 18 are “activated” or “powered” according to a specified pattern. For example, in one embodiment, the first antenna loop 14 is activated and obtains signals from tags 102 within its first spatial area 16, and subsequently and serially, the additional antenna loop 18 is activated and receives signals from the tags 102 in the additional spatial area 20. Since the first spatial area 16 and additional spatial area 20 overlap, the tags 102 that are placed in a “dead spot” or low probability reading area in one of these spatial areas 16, 20, are read or identified due to its relative position in the other spatial area 16, 20. In this manner, by switching, alternating or otherwise activating in a specified pattern the antenna loops 14, 18, the accuracy of the antenna arrangement 10 is greatly improved. Of course, there will often be tags 102 that are positioned such that they are identified by both antenna loops 14, 18. However, the reader 24 includes the appropriate resolution software or circuitry to remove duplicate identifications, as well as recognize non-identifications.
An embodiment using three antenna loops (i.e., the first antenna loop 14 and two additional antenna loops 18) is illustrated in
In operation, and as best seen in
Next, in Step 2 in
In order to more effectively identify tags 102 positioned in the X-Y orientation, a second antenna module 34 could be utilized. This second antenna module 34 (together with the first antenna module 12) is illustrated in
In the embodiment of
Further, in this embodiment, and as with the first antenna module 12, the fourth spatial area 38, fifth spatial area 42 and sixth spatial area 46 all overlap each other and are also operated or “read” in a sequential or serial pattern. Therefore, as seen in
It is envisioned that Steps 1-6 can be performed in any suitable manner. For example, as seen in
Another embodiment of the antenna arrangement 10 of the present invention is illustrated in
In another embodiment, and as illustrated in
As seen in
The scan time for a large area, such as a large substrate 21 having many items 100 (and corresponding tags 102) thereon could be decreased. Specifically, as seen in
Another preferred and non-limiting embodiment is illustrated in
Further, in this embodiment, a third antenna module 72 and a fourth antenna module 74 are positioned under or in a stacked relationship with respect to the first and second antenna modules 12, 34. In addition, the third antenna module 72 and fourth antenna module 74 are horizontally spaced and substantially coplanar with each other. The embodiment of
In a single wave switching module, a larger amplitude is obtained, as well as a larger field strength. In a double wave switching arrangement, which uses a power splitter 50, a smaller amplitude is obtained, which results in a decreased field strength, however the reading or scanning time will be much improved. Therefore, balance between the field strength and the timing requirements can be tailored depending upon the operational requirements and application of the antenna arrangement 10. For instance, to track a small item 100, such as a pharmacy bottle or the like, the field strength will be a priority over the scanning or reading time. However, for a big item 100, which exhibits excellent energy transfer between the tag 102 and the antennae (as bigger items 100 use bigger tags 102), the reduction in scanning or reading time will take priority.
Yet another embodiment is illustrated in
Accordingly, the present invention provides an antenna arrangement 10 and system having improved identification characteristics and which allows for the identification of target transponders or tags 102 in every position. In addition, the present invention provides a uniform three-dimensional magnetic pattern having a high-powered magnetic field. As discussed above, prior art cube-based and complex antenna arrangement do not produce this required power for such an application. The presently-invented antenna arrangement 10 dynamically modifies the antenna wire position closest to the tag 102, which provides maximum energy transfer. In addition, the combination of multiple antennae, antenna “ON”/“OFF” controls, in-phase and out-of-phase controls, together with temporal controls, produces this required field. Still further, the antenna arrangement 10 of the present invention allows for the modification of the antenna wire form and position, as well as phase manipulation as a substantially static process, which does not require any moving parts. In addition, the antenna arrangement 10 and system may be controlled by an antenna control device 52, computing device 70, etc., thereby providing an arrangement having control characteristics that require a singularly planar antenna system that produces this three-dimensional magnetic field.
Although the invention has been described in detail for the purpose of illustration based on what is currently considered to be the most practical and preferred embodiments, it is to be understood that such detail is solely for that purpose and that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover modifications and equivalent arrangements that are within the spirit and scope of the appended claims. For example, it is to be understood that the present invention contemplates that, to the extent possible, one or more features of any embodiment can be combined with one or more features of any other embodiment.
This application claims the benefit of priority from U.S. Provisional Patent Application No. 60/664,166, filed Mar. 22, 2005, which is incorporated herein by reference in its entirety.
Number | Name | Date | Kind |
---|---|---|---|
5266922 | Smith et al. | Nov 1993 | A |
6166706 | Gallagher et al. | Dec 2000 | A |
6263319 | Leatherman | Jul 2001 | B1 |
6445297 | Nicholson | Sep 2002 | B1 |
6696954 | Chung | Feb 2004 | B2 |
6738025 | Carrender | May 2004 | B2 |
6943688 | Chung et al. | Sep 2005 | B2 |
6989796 | Rahim | Jan 2006 | B2 |
Number | Date | Country |
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WO 03090310 | Oct 2003 | WO |
Number | Date | Country | |
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20060214864 A1 | Sep 2006 | US |
Number | Date | Country | |
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60664166 | Mar 2005 | US |